The present invention is directed to novel taxanes which have utility as antileukemia and antitumor agents.
The taxane family of terpenes, of which taxol is a member, has attracted considerable interest in both the biological and chemical arts. Taxol is a promising cancer chemotherapeutic agent with a broad spectrum of antileukemic and tumor-inhibiting activity. Taxol has a 2'R, 3'S configuration and the following structural formula: ##STR1## wherein Ac is acetyl. Because of this promising activity, taxol is currently undergoing clinical trials in both France and the United States.
Colin et al. reported in U.S. Pat. No. 4,814,470 that taxol derivatives having structural formula (2) below, have an activity significantly greater than that of taxol (1). ##STR2##
R' represents hydrogen or acetyl and one of R" and R'" represents hydroxy and the other represents tert-butoxycarbonylamino and their stereoisomeric forms, and mixtures thereof. The compound of formula (2) in which R' is hydroxy, R'" is tert-butoxycarbonylamino having the 2'R, 3'S configuration is commonly referred to as taxotere.
Although taxol and taxotere are promising chemotherapeutic agents, they are not universally effective. Accordingly, a need remains for additional chemotherapeutic agents.